Frostbite with tissue necrosis of unspecified knee and lower leg

• birth trauma (P10-P15)
• obstetric trauma (O70-O71)

code to identify any retained foreign body, if applicable (Z18.-)

• Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
• The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

hypothermia and other effects of reduced temperature (T68, T69.-)

The appropriate 7th character is to be added to each code from category T34

frostbite with tissue necrosis of ankle and foot (T34.8-)